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This paper reviews the major components unique to light truck four-wheel drive systems and their effect on vehicle performance. It analyzes the tractive capabilities of four-wheel drive in comparison with front and rear drive under various load, grade, and friction conditions. The effects of different types of inter-axle differentials and the pros and cons of various front suspension and drive systems for 4x4's are also studied.

Optional safety features were made standard on American cars twelve years ago when the first highway and traffic safety bills were signed into law. All new cars, large and small and all price classes, were required to comply. However, the consumer must be made aware of present safety standards. There is government influence to purchace small cars in order to conserve fuel; yet statistics show a three to one ratio of death or serious injury to occupants of small cars over those of large cars. The consumer's choice of vehicle and equipment greatly affects his safety and the safety of his passengers.

This paper discusses in some detail the mathematical model input data used by the Vehicular Noise Control Department of the General Motors Environmental Activities Staff to project the effects of various medium and heavy truck noise regulation strategies on future community noise levels. The model projects that, for two typical traffic situations, the reduction of new truck sound levels below current requirements does not result in a corresponding decrease in community noise levels. Furthermore, the potential benefits anticipated from the implementation of new truck noise regulations will not be realized without the effective enforcement of operator in-use standards and the control of truck tire noise.

Successful automotive weight reduction with high strength-to-weight ratio steels has caused re-evaluation of the basic structural design parameters. This paper introduces the new concept of “Kinetic Modulus” which describes the nature of materials in motion. Kinetic modulus is influenced by stress and strain amplitude, yield strength and the number of loading cycles. The scope of kinetic modulus encompasses: elastic, secant, dynamic and tangent moduli; each of which is a specific case of kinetic modulus at a particular condition. Theoretical and experimental results are presented to support this concept. They show that high strength steel has higher dynamic stiffness and improved vibration response in structures as compared to that of lower strength steel. Thus, high strength steel (“Stiff Steel”) can be used advantageously in stiffness controlled automotive structures to achieve greater weight reductions.

Patents, copyrights, trade secrets, and trademarks are exemplified in an easily under stood language. Each form of protection is applicable to certain types of intellectual property, although there may be over laps. Since most types of property fall logically into one area or the other, the decision as to which type of protection to pursue is normally not difficult.

Customer satisfaction is the tie which binds engineering and marketing together in any business. It is the driving force of the whole economic system. And the second common bond - the relentless pursuit of facts.

The development of dual-phase (ferrite-martensite) microstructures in hot- and cold-rolled sheet can be accomplished by selecting the hardenability of the steel in relation to the particular thermal cycle used in processing. Intercritical continuous annealing of hot- or cold-rolled sheet when coupled with air- or accelerated-cooling rates can produce dual-phase microstructures in relatively low-alloy steels. In addition to the development of the required ferrite-martensite microstructure that produces a continuous stress-strain curve with low yield strength and high tensile strength, the development of enhanced ductility must be considered. The interrelationship among steel hardenability, processing conditions, microstructure, and mechanical properties is considered for both laboratory- and production-processed intercritically continuous-annealed sheet.

Eight high-strength, low-alloy (HSLA) steels were dynamically strain aged in the temperature range 100-600°C, with strains from 1.5 to 6% and strain rates from 1 x 10-4 to 2 x 10-2. Subsequently, changes in tensile, notch impact and fatigue properties were determined. The data indicate that in forming HSLA steels in the dynamic strain aging range, the temperature should be between about 250 and 400°C, with the higher end of the range being preferred. The strain rate is unimportant. A dual-phase Mn-Mo-Cb steel gave the best response to this treatment. The room temperature tensile properties for this steel were: At the forming temperature, yielding was continuous and the rate of work hardening was more rapid than at room temperature.

This paper reviews some of the progress that has been made in recent years in the transportation field by behavioral scientists and human factors engineers. The major areas covered are public transportation systems, railroad systems, highway systems, and personal transportation systems. The report suggests what future problems may be encountered in these areas that will need the attention of human factors specialists.

A study was undertaken to describe the effects of various annealing treatments, both intercritical and supercritical, on the mechanical properties and microstructures of six dual-phase, Mn-Si, Mn-Si-Cr, Mn-Si-Mo and Mn-Si-V steels having nearly equal hardenability. It has been found that the combination of tensile strength and total elongation after intercritical treatments may be slightly better than that after supercritical treatments. Although hardenabilities of these six alloys were more or less equal, it appears that the strength-ductility relationship varies a little (though not very significantly) with chemistry. The strength-ductility behavior of Mn-Si-Cr steels compares quite favorably with that of commercial Mn-Si-V steels with optimum processing conditions for both. It has been confirmed that the tensile strength of dual-phase steels is primarily a function of the hard-phase (mainly martensite and bainite, if any) content at a given ferrite grain size.

Stiffness and vibration frequency of automotive structures are shown to be dependent upon an effective modulus. Under typical loading conditions the effective modulus would be much less than the elastic modulus. The concept of the effective modulus ratio is introduced as a dimensionless quantity to describe the change in apparent modulus. It is shown that HSLA steels, specifically HI-FORM 50 and HI-FORM 80, are less affected than AISI 1005 steel.

The increased usage of high-strength, cold-rolled steels has revealed differences in spot welding characteristics between the thin, high strength steels and the plain carbon steels commonly used in the automotive industries. The response of four, 275 MPa yield strength, cold-rolled steels to a variety of spot welding schedules was determined through an evaluation of mechanical property and fracture appearance tests. The results of this study were compared to various weld quality evaluation criteria and suggestions for a revised criteria were proposed.

The spot welding characteristics of VAN-QN (80), a dual-phase HSLA steel, were examined with regard to the strength and ductility of spot welds under static, impact and cyclic loading and compared to a conventional V-N HSLA steel and SAE 1008 low carbon steel. The maximum tensile shear strength of VAN-QN (80) spot welds was found to be proportional to the thickness and ultimate tensile strength of the base metal. VAN-QN (80) spot welds, therefore, were only slightly lower in strength than those in a conventional 80 Ksi yield strength HSLA steel but up to twice the strength of welds in low carbon steel. Weld ductility was lower for VAN-QN (80) than for low carbon steel but greater than for conventional HSLA steel and increased with material thickness. The impact and fatigue properties of VAN-QN (80) welds were similar to those in conventional HSLA and low carbon steels.

Microstructure, mechanical properties, lab formability and ageing response of two as-hot-rolled dual phase steels, a heat treated dual phase steel, and microalloyed 345 MPa and 550 MPa (50 ksi and 80 ksi) steels are compared. Measurements and implications on press performance of: work hardening behaviour, strain rate sensitivity, elongation before necking, resistance to edge cracking, and uniformity of properties are discussed. Formability of both heat treated and as-hot-rolled dual phase steels was found to be similar at a common strength level, their formability lying between that of the 345 MPa and 550 MPa steels.

A new three-speed automatic transmission has been designed, developed and is being produced in the U.S. by the Chrysler Corporation for its new family of front wheel drive vehicles. The transmission was designed around the Chrysler-proven TorqueFlite concept. The features of the new transmission include a “folded” construction for installation in a transverse power train. The case is a one-piece aluminum die cast housing and contains the final drive and differential unit. This paper describes the design and development of this new automatic transmission.

The extent of automatic transmission fluid oxidation is compared for short term bench transmission tests with long term vehicle tests. The technique of Blotter Spot Analysis is emphasized for the comparison. Blotter Spot Analyses can help decide when an automatic transmission fluid should be changed in severe service.

The over-riding social importance of automotive fuel economy and power plant exhaust emissions is discussed in relation to proposed alternatives to the spark-ignition passenger car engine. Some engineering and use criteria for the selection of alternatives are proposed, and several alternative power plants are explored in their frame work. Three gas turbine types are discussed as alternatives, and a brief history of two-shaft turbines is presented. The influence of various automatic transmissions on passenger-car fuel economy and driveability is summarized. This paper concludes that automatic, continuously variable transmission functions can be achieved with a three-shaft turbine power plant with excellent fuel economy and at lower cost.

The scope of the hybrid propulsion systems studies that have been developed by FIAT Research Centre, is the energy consumption evaluation in comparison with conventional traction drives. After a general study on the hybrid propulsion systems, mathematical models have been developed for the evaluation of performances and energy balance. The construction of a prototype with parallel hybrid propulsion system has been completed to validate the computer simulation models. Computer and on road tests results are reported. Criteria used to select the parameters to the optimization of the system are discussed.

An automatic transmission fluid has been developed which can meet the needs of transmissions designed for either friction modified or non-friction modified fluids. Approved under the DEXR0N*-II and M2C138-CJ specifications, it also meets all the requirements of the M2C33-F (Type F) specification except for the friction modifier content. Since use of a friction modified fluid in Type F applications would represent a radical departure from current recommended practice, data, both pro and con, on the concept are presented.

This computor simulation analysis has been tried as an efficiency study using the Daihatsu Engine/Electric Hybrid 1.5 ton truck which has the “DHS” systems, and run in accordance with three driving patterns such as U.S. LA-4, Australian eight and Japanese ten modes. Every input data are measured and/or evaluated through the actual test and, for the selection of the four driving modes the “DHS” has, three cases of specific fuel consumptions of 190,200 and 210 gr/PS gr/PS · h contour lines are used. As results, the accurate differences of the fuel consumption has been found under every cases.